<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        html,body{
            width: 100%;
            height: 100%;
            display: flex;
            justify-content: center;
            align-items: center;
        }
        .box{
            width: 500px;
            height: 500px;
            position: relative;
        }
        .box>div{
            position: absolute;
            left: 50%;
            top: 50%;
            transform: translate(-50%,-50%);
        }
        .dotted{
            width: 15px;
            height: 15px;
            border-radius: 50%;
            background-color: skyblue;
            box-shadow: skyblue 0 0 10px;
        }
        .pulse1,.pulse2,.pulse3{
            border-radius: 50%;

            /* 注意不要给边框，给盒子阴影就好 */
            box-shadow: skyblue 0 0 5px;
        }

        .pulse1{
            animation: pluse linear 1s backwards 0s infinite;
        }

        .pulse2{
            animation: pluse linear 1s backwards 0.5s infinite;
        }

        .pulse3{
            animation: pluse linear 1s backwards 1s infinite;
        }

        @keyframes pluse {
            /* 也许你会疑惑为什么不使用scale进行波纹效果的实现呢？其实很简单，因为scale会连着box-shadow一起放大，会比较难看。这里一定要注意，scale是放大一个元素的所有东西，scale虽然很优秀，但是真的不是适用于所有场景 */
            0%{
                width: 10px;
                height: 10px;
                opacity: 1;
            }

            25%{
                width: 25px;
                height: 25px;
                opacity: 0.75;
            }

            50%{
                width: 40px;
                height: 40px;
                opacity: 0.5;
            }

            75%{
                width: 55px;
                height: 55px;
                opacity: 0.25;
            }

            100%{
                width: 70px;
                height: 70px;
                opacity: 0;
            }
        }
    </style>
</head>
<body>
    <div class="box">
        <div class="dotted"></div>
        <div class="pulse1"></div>
        <div class="pulse2"></div>
        <div class="pulse3"></div>
    </div>
</body>
</html>